A bicycle disc brake system moves a brake pad in accordance with the operation of a brake lever to generate braking force by producing friction with a brake pad friction member and a disc rotor. A conventional brake pad includes a friction member and a support member, which supports the friction member. A metal pad is known as such a brake pad. The friction member of the metal pad is composed of a metal composite material and substantially does not include resins. In such a metal pad, the friction member has a large thermal conductivity. This makes it difficult to couple the friction member and the support member with an adhesive agent. Thus, the friction member and the support member need to be mechanically coupled to each other. However, in comparison with coupling that is performed with an adhesive agent, additional components and steps are required to perform mechanical coupling such as swage-coupling.